Unsafe drinking water can have disastrous consequences. Therefore, the Environmental Protection Agency (EPA) sets standards for tap and public water systems in the United States under the Safe Drinking Water Act (SDWA). Potable water tanks are one key component of water systems, and eventually they develop coating failures or leaks. Keeping the different parts of a potable water system sufficiently maintained protects the integrity and dependability of the components and thus the water system. Taking water systems out of service and draining for maintenance is impractical and often prohibitively expensive. Spot repairs made with the system “in service” or with only minimal shut-down give water system operators a valuable tool for maintaining water infrastructure.
Diving is the most common method for inspection and repair of potable-water-storage-facilities. Divers wear industry standardized suits, so at no time does the body come in contact with the stored water. The American Water Works Association (AWWA) Standard for Disinfection of Potable Water Storage Facilities is one industry standard that governs this work. This standard requires that divers and equipment be sanitized with AWWA compliant chlorine solutions before entering the tank. Further, many states require that all components of a water treatment or distribution system be approved for potable water service pursuant to NSF/ANSI 61: Drinking Water System Components—Health Effects. However, current industry standard is to apply coatings underwater with potable water exposed to the uncured coating, although the uncured coating is not approved for contact with potable water. For instance, Liquivision Technology of Klamath Falls, Oreg., promotes diving services which include application of an underwater coating which comes into contact with the water prior to being cured, as seen on YouTube at https://www.youtube.com/watch?v=ppf8eYVXuec and other places.
Consequently, there remains a need for systems and methods for safely repairing potable water tanks and other portions of a water system when submerged within a full tank or system.